Automatic draft control for heating apparatus



H. E. SPEARS.

AUTOMATIC DRAFT CONTROL FOR HEATING APPARATUS.. APPLICATION man remi-1. 1921.

iication.

UNIT@ `STATES HARRY ii. srnAas, or BALTIMORE, MARYLAND. v

AUTOMATIC DRAFT coNTitoL ron iinATiNe ArrAnATU-s.l y

Application filed February 14, 1921. Serial No. 444,958.

To all whom t may concern:

Be it known that l, HARRY E. SPEARS, a

citizen of the United States, residing at Balitimore city, State of Maryland, have invented certain new and useful improvements in Automatic Draft Controls for Heating Apparatus, of which the following is a speci- This invention relates to apparatus for operating thedraft doors, dempers and the like of furnaces, and its object is to provide a novel and improved mechanism which is time-controlled, so thatit mayl operate at a predetermined time. y i,

The object stated is attained by means of a combination and arrangement of parts to be hereinafter described and claimed, and in order that the same may be better understood, reference is had to the accompanying drawing forming a part of this specification.

1n the drawing, y i

Y Figureil is a perspective view showing the application of the invention; Fig. 2 is an elevation of a time-controlled latch device, and Fig. 8 is a vertical section on the line 3-3 of Fig. 2. l

Referring specifically to the drawing, 5 denotes an ordinary furnace which is'provided with a feed door (Sand a bottom draft door 7. It .is the usual practice ofhouseholders, at night, to cover the fire in the furnace, partly open the feed door, and entirely close the draft door, so that the fire may keep up until the morning. 1n order that a hot fire may be obtained in the morning the fire door must be closed and the draft door opened, this-necessitating a trip to the cold cellar or other place where the furnace is located. The invention has been designed to avoid the inconvenience of manually operating the fire and draft doors in the manner described, this being accomplished by a mechanism which automatically operates at a predetermined time, and which will now be described.

Alongside the furnace 5 is mounted an upright post or other suitable stationary support 8 carrying at its upper end a housing 9 which supports an ordinary alarmclock 10. As is well understood, an alarmwinding key 11 projects from the back of the clock-casing, and this key rotates when the alarm goes off. The front of the housing 9 has an opening 12 to expose thekface of the clock, and inside the housing is a partition wall 18 to whichis pivoted, as shown.

at 14, a lever 15 which projects at one'end from the; corresponding end of the housing through an openingl therein. `The wall 13. also carries -a stop pin 17 against which nr orrtrCEE the lever is held pulled downwardly by 'a spring 18l rlhe wall 13 also carries a pivoted detent i.

19 having a hook-shaped upper end 20 to engage the inner end of the lever 15to hold tliesame down against the stop 17; .The detent is pivoted to the .wall 13 as shown. at 21f,

in such' a position that its lower end comes alongside the key 11 as clearly shown in Fig. 2. The wall 18 also carries a stop pin `22 against which the-,detent 19 is held by. a

spring 23., lt will bek evident from the foregoing that when the key'11.l starts to turn, it swings thev detent 19 in a direction-.to trip 'off the lever 15, thereby releasing the latter.

@n they outer end jof the. lever 15 which projects from the housing 9 isloosely hung Va rod.cr link 2A ,having its lower end connectedto the upper end of a coiled spring 25, which latter is anchored at its lower end to the post 8, and is retained in vertical position alongside the post hy guides 26.

Above the spring 25, the post 8 carries a double pulley 27 over which passesL a light chain or other hauling line 28 which is formed into a loop below the pulley 27,

said loop being made fast to the upper end of the spring. From the pulley 27 the two ends of the line 28 pass to the doors 6 and `7 one end being connected to one door and the other end to the other door, the end which is connected to theV draft door 7 passing over a guide pulley 29 suspended from the ceiling or some' other overhead support.

Fig. 1 shows the mechanism set andy ready for operation, the door 6 being partly open and the door 7 closed. The alarm has been set to go off at the desired vtiine whenthe p door 6 is to close and the door 7 to open. The spring 25 has been placed under tension by pulling'the rod 24 upwardly and hanging 15, and the latter has been locked by the detent 19. The key 11 has been placed so that its fiat side engages the detent and locks the same. When the alarm goes off, the key 11 trips the detent 19 off the lever 15, allowing the latter to tilt so that the rod 211 slips off the lever 15, which releases the spring 25, and the latter upon pulling down on the looped portion of the line 28 hauls in the two ends of the line so that the door it on the outer. end of the lever y 6 is closed and the door 7 is swung open. rlhe lire in the furnace 5 now begins to burn and warm up the house. The mechanism can be set at night to operate at any desired time in the morning andkit operates entirely automatically after it is set, so that the house will be comfortably warm when' vthe occupants arise. Y

The preferred embodiment of the invention has been illustrated but it will he under- ;stood'that various changes and modifications may be made without a departure from the vSpirit and scope of the invention as claimed hereinafter. Thus, a weight may be substituted for the spring.

I claim:

1.1As a unitary article of merchandise, the draft-controlling attachment for furnaces, comprising a post, a pulley thereon, a normally detained lever mounted on said post and having one end projecting over said pulley, time-controlled mechanism se-l cured onsaid post and including means to release said lever, a helical Vretractile spring extending up and down one face of the post under said projecting end of the lever and undersaid pulley and having its lower end anchored tothe lower part of said post,

guiding means on said face of the post for holding said spring against lateral movement while permitting longitudinal expansionand contraction ofthe spring, a link connected-to said lever and spring for holding the latter under tension and for relieving said tension When the lever is released, and a hauleline secured to said spring and adapted to be attached to a draft-door and to guiding means in correlation with said pulley, for controlling said draft-door.

2. As a unitar article of merchandise, the draft-control ing attachment for furnaces, comprising a post, a pulley thereon, a--normally detained lever mountedy on said post and having one end extending over said pulley, time-controlled mechanism secured on said post and including means to releasey rsaid lever, means under said end of the lever and connectible thereto for holding the downwardly pulling means against operation, means secured on the post for holding the downwardly pulling means in contiguity with'the post while permitting vertical movement of the pulling means and guiding it in such movement,and a 'haul-line, secured to said downwardly-pulling downwardly pulling 'means and attachable Y to a furnace-door, said haul-lineV being Y cooperative with said pulley and other guiding means for controlling said furnace-door, substantially as shown.

In testimony whereof I aiiX my signature..

HARRY E. SPEARS. 

